The primary add-in adapter card form factor for computing devices is now the PCI Express (PCIe) specification which specifies four different lengths of connectors. Most system designers design to allow cards with smaller bandwidths, e.g., x4 or x8, to fit into the longest x16 connector on a server system board. However, when a card is installed in a connector that is longer than the card edge connector, the installed card is unstable and has a tendency to want to rock out of the connector, which in turn can cause the card to function incorrectly, e.g., due to loss of connectivity.
Present methods of dealing with this are to have retention on both ends of the topside of the card, or to fasten the card into the chassis with screws. Screwing down the card takes extra time for service and installation, while adding front side retention on the card requires extra parts and space within the chassis.
The PCIe x16 card specification contains a feature that extends down in front of the front end of the connector to latch into a latch that is connected to the slot, but this feature is not present on many adapter cards.
What is needed in the industry is a method to ensure any PCIe adapter card stays vertical, i.e., does not rock out of the slot, and can still use quick toolless methods to retain the card within the slot.